A conventional double-story parking system as shown in FIG. 10 includes a platform P movably supported by four columns C, which platform P can be raised by hydraulic means to form a parking frame of two stories for parking two cars C1, C2 thereon.
However, it still has the following drawbacks:
1. When it is intended to use the car C1, parked on the second floor, the lower car C2 should be first driven away from the parking frame to allow the descending of the platform P for leaving the upper car C1 from the platform P, causing inconvenience for the owners or drivers of the two cars C1, C2.
2. Similarly, if the "first floor" is already occupied by a lower car C2, how can the "second floor" of platform P be used for parking an upper car C1?
3. The raising or descending mechanism of the platform actuated by hydraulic system is quite complex and will increase its installation cost.
The present inventor has found the defects of the conventional parking frame and invented the present parking apparatus of simpler construction and convenient operation.